Primary galvanic battery



Patented Mar. 6, 1928.

UNITED STATES PATENT. OFFICE.

ERNST WALDEMAR JUNGNER, OF KNEIPPBADEN, SWEDEN.

PRIMARY GALVANIC BATTERY.

No Drawing. Application filed June 1, 1920, Serial 385,785, and in Sweden February 14, 1919.

This invention relates to primary galvanic batteries in which a porous electrode is used to which is supplied either an active gas or atmospheric air for obtaining a depolarizing 5 action.

In-gas batteries proper as hitherto constructed the active gas consists of chlorine, hydrocarbon, carbon monoxide, sulphur dioxide, or other suitable gas which-during the work of the battery is caused to react with another gas (hydrogen in chlorine batteries and oxygen when the other gas is oxidizable). The active gas in suchbatteries is introduced in the pores of a porous carbon electrode which is submerged in a suitable electrolyte. If the porosity of the carbonelectrode is great and if the pores at the same time are sufiicientlysmall it is possible to generate very strong currents with such batteries. It has, however, hitherto not been possible to generate constant currents of long duration for the reason that thepores of the carbon'electrodes become rapidly filled with electrolyte whereupon they nearly'completely lose their ability of condensing and activating the gases. -A further draw-back;

in gas batteries is that a carbon electrode which has once been soaked by the electrolyte cannot be restored to its original. state by drying it as a dried electrode when reintroduced in the electrolyte is practically instantaneously soaked by the same.-

.Similar drawbacks are found-also in usual primary galvanic batterieshaving a metal as active substance and depolarizer of atmospheric oxygen, inasmuch as it has been impossible in such batteries in which the depolarizing electrode consists of porous carbon, to maintain a permanent and con- 40 stant depolarizing action without the use of a special depolarizin substance anoxygen transferring oxide) w ich efi'ectst e depolarizatiou and notwithstanding ditficulties have arisen from the entry of the electrolyte into the pores of the carbon electrode.

The chief object of the present invention is to remove said drawbacks and difliculties in gas batteries proper, as well'as in bat teries havin active metal electrode that is depolarized y means of atmospheric oxygen and to make it possible to generate by means of such batteries strong and constant currents during practically unlimited eriods. The invention consists, chiefly, in t e provision of a porous carbon electrode, the pore walls of which are coated. with a thin layer of parafline in such manner that the natural pore volume of the carbon is to an essential degree maintained.

Electrodes manufactured according to this invention have such a small adhesion to the" electrolyte of the battery that the electrode has no tendency or only a very little tendtheir walls as, a fine coating. A porous elec- .trode treated in this manner with a solution of 5 parts by welght of parafline and 100 partsby' weight of .solvent maintains during many years its full activity, inasmuch as the ores of the electrode only extremely slow y become soaked by the electrolyte. The fact that the parafiine is a non-con uctorfor electric currents has no material influence on the action of the electrode when the quantity of parafiine introduced into the electrode is not too high. The quantity of parafline should preferably not exceed 10' to 15 percent b weight.

The form. 0 the electrodes may be the same as usually used in gas batteries and galvanic batteries depolarized by atmospheric ox gen. Electrodes for gas elements are accor ingly preferably made hollow with rectangular cross-section and with a supply pipe for the active gas. Electrodes for atteries having depolarization by means of the atmospheric oxygen are preferably made so that they have a large horizontal surface and when used in the batteries they are dipped into the electrolyte only to a small epth (a few millimeters).

Havin now described 'my invention I declare t at what I claim is 1. A porous electrode for electric batteries,

c'onsistingofporous carbon the pore walls of which are coated with a thin layer ofparafiine in such manner thatthe natural pore volume of the carbon is maintained to an essential degree.

2. A rimary electrode battery, comprising an e ectrolyte and a porous carbon electrode adapted to take up oxygen from the atmosphere, and having its ore walls coated with a thin layer of para e in such manner that the natural pore volume of the cargas in its pores, the pore walls of said elecbon is maintained to an essential degree and trode being coated with a thin layer of the entry of the electrolyte into the pores of parafline so as to prevent the entry of the I the electrode is prevented. electrolyte into the pores of the electrode.

5 3. Anelectric gas battery, comprising an In testimony whereof I have signed my electrolyte, a gas as active substance, and a name. porous carbon electrode for taking upsaid ERNST WALDEMAR J UNGNER. 

